Messages in this thread | | | Subject | Re: [PATCH v2 1/2] pinctrl: Add driver for Awinic AW9523/B I2C GPIO Expander | From | AngeloGioacchino Del Regno <> | Date | Sat, 23 Jan 2021 00:39:13 +0100 |
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Il 22/01/21 10:59, Linus Walleij ha scritto: > On Mon, Jan 18, 2021 at 3:38 PM AngeloGioacchino Del Regno > <angelogioacchino.delregno@somainline.org> wrote: > >> By the way, this is really LEVEL irq, not EDGE... To avoid any >> misunderstanding, I think that the best way to show you what I >> am seeing is to just copy-paste the relevant piece from the >> datasheet for this hardware (it's not a confidential datasheet >> and freely found on the internet). >> >> Check this out: >> " External MCU is required acknowledge by INTN pin. INTN is open-drain >> out- >> put, low-level active, and need external pull-up resistor. > > This talks about what polarity (active low) the pin from the expander > to the SoC/CPU is. It has nothing to do with the line into the > expander. > >> When AW9523B detect port change, any input state from high-level to >> low-level or from >> low-level to high-level will generate interrupt after >> 8us internal deglitch. " >> >> ...but since the datasheet is sometimes unclear about "things" (I am >> mostly sure that they have translated it to english from chinese), I >> have actually checked whether the INTN pin was pushed LOW when one of >> the inputs goes from HIGH to LOW.. and.. it does... and as you imagine >> yeah.. it's slow.. and yes, as slow as you can imagine. :) >> >> So, in short, this chip is raising an interrupt when any input changes >> state, regardless of the change being LOW->HIGH or HIGH->LOW. > > This means that the expander only supports > IRQ_TYPE_EDGE_BOTH and nothing else. > > "port change" above means edges. > > Augment your driver to only accept this type. > > The consumers better request IRQ_TYPE_EDGE_BOTH > (from a device tree for example) and consumers better > handle the fact that they get interrupts on both rising > and falling edge as well, else they may need special > code to handle it. This is not a very nice feature of > the expander, it would be more helpful to users to > get interrupts on only rising or only falling edges, but > as written, it will generate interrupts on both transitions. > > Yours, > Linus Walleij >
I see the reading mistake now... oh wow, that was... sad, from me. I will fix this ASAP and will send back a v3.
Thank you!
- Angelo
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